1. Field of the Invention
This invention relates to a method of treating a water containing waste and an apparatus for carrying out the method. Particularly, this invention relates to a method and apparatus for treating a water containing organic waste such as animal and human excrements, fish processing wastes, sludges comprising dead microorganisms, sludges from paper industry or fruit processing wastes, and a water containing inorganic waste such as sludges from chemical or sewage disposal plants.
2. Description of the Prior Art
There have been various proposals for treating a water containing organic or inorganic waste. It has been proposed to treat excrements of domestic animals by mixing the excrements with calcium oxide thereby attempting to dry the mixture by the exothermic reaction of calcium oxide with water contained in the excrements. However, the mixture thereby obtained still contains a substantial amount of water and gives off an offensive filthy odor until it is cooled. The mixture is not granulated and therefore is not yet suitable for disposal or for use as a fertilizer. As the mixture still has a high content of water, it cannot be easily processed by an ordinary pelletizer. It is therefore necessary to further remove water, before subjecting the mixture to a granulation step, by subjecting the mixture to a separate drying operation. The emission of the offensive filthy odor creates a troublesome and annoying problem in the handling and transportation of the mixture, and a loss of heat during the transportation of the mixture from the reactor to a dryer adversely affects the economy of the fuel consumption of the drying operation.
On the other hand, inorganic wastes such as sludges from chemical or sewage disposal plants usually comprise very fine particles in a mashy state. Because of their nature, the handling and transportation of such sludges are troublesome and very difficult. It is very difficult to remove water from such sludges either by a filter press or by a dryer. They used to be buried under ground, however, they frequently contain noxious elements such as heavy metal ions or sulfate ion, which create pollution problems. It has been proposed to mix such a sludge with a cement thereby to obtain a concrete product. This method is costly. Besides, the concrete product thereby obtained is brittle and not suitable for use as a construction material. Water soluble noxious substances are still likely to ooze out of the product.